<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .box{
            width: 300px;
            height: 200px;
            border:1px red solid;
        }
        .t1{
            height: 100px;
            width: 240px;
            border:1px red solid;
            float: left;
        }
        .t2{
            height: 50px;
            width: 50px;
            border:1px red solid;
            float: left;
        }
        .t3{
            height: 50px;
            width: 50px;
            border:1px red solid;
            float: left;
        }
    </style>
</head>
<body>
<div class="box">
    <div class="t1"></div>
    <div class="t2"></div>
    <div class="t3"></div>
</div>
</body>
</html>